The present invention relates to a computer system in which two or more kinds of storage networks exist between a storage device and a computer, and more particularly to the technology that sets information in a computer system by use of network identifiers.
In a configuration in which a network (more specifically, a storage network) exists between a storage device and a host computer, information settings may be made between the storage device and the computer. For example, the access limit of an access from the host computer to a logical unit in the storage device is established, or the priority control QoS (Quality of Service) of I/O processing or the like is performed. In this case, an identifier of the host computer on the storage network is in general used.
For example, for a system in which a storage network using a fiber channel (FC) connects between a storage device and a host computer, a method for setting the access limit of an access from the host computer to a logical unit in the storage device is in general achieved by the technology as described in patent document 1.
According to the technology of Japanese Patent Laid-open No. 2000-339225 (patent document 1), a LUN access management table is stored in a non-volatile memory in a storage device. This table stores the correspondence of an identifier on the FC network (N_Port_Name, or WWN (World Wide Name)), by which a host computer is uniquely identified, to a logical unit number (LUN) of a logical unit in a storage device, said logical unit being permitted to be accessed from the host computer. The communication security between the storage device and the host computer is achieved by executing a filtering function in which the storage device selects only communications to which the access permission to access a logical unit in the storage device is given. To be more specific, on the basis of identifier information on the FC network that is stored in the management table, only I/O requests to which the access permission is given are selected from among I/O requests that have been issued from the host computer, and that have arrived at the logical unit. As a result, a normal access to the logical unit is ensured.
In addition, as another example, for a system in which the FC network connects between a host computer and a storage device, a method for setting QoS of I/O processing for a logical unit in a storage device of a host computer is in general achieved by the technology as described in Japanese Patent Laid-open No. 2002-108567 (patent document 2, corresponding to Published Patent Application U.S. 2002/003839A1).
According the technology described in patent document 2, a host information management table is stored in a non-volatile memory in a storage device. The host information management table includes: an identifier on the FC network (WWN), by which a host computer is uniquely identified; and a target value of I/O processing speed. Every time a command set of I/O processing is issued, QoS of I/O processing for a storage device of each host computer is guaranteed. In other words, the priority control QoS of the I/O command set arriving at a logical unit is guaranteed on the basis of identifier information on the FC network that is stored in the management table.
On the other hand, for a storage network between a storage device and a host computer, what are being formulated in recent years are the specifications of iSCSI (the specifications, the standardization of which is being promoted by IETF). The iSCSI executes I/O processing through a network using the Internet Protocol (IP), which is in general used for communications between host computers.
As is the case with the FC network that is taken as an example in the embodiments of patent documents 1 and 2, the iSCSI achieves the I/O processing between a host computer and a storage device by encapsulating in a protocol packet a command set used to access the storage device, such as a SCSI command, and then by transmitting the protocol packet on a network to communicate between the host computer and the storage device. By use of this technology, it is possible to easily achieve the wide-area access control of storage devices, which was difficult to achieve because of its cost, the limit in the communication distance, and the like, in the past. In addition, the simplification of management can also be expected by applying the mature IP network management technologies to the management.
Also to the iSCSI specifications, it is possible to apply the access limit between a host computer and a storage device, and the priority control QoS of I/O processing, which are disclosed in patent documents 1 and 2. In such a case, an identifier on the IP network is used for settings.